(a) Field of the Invention
The present invention relates to a system for manufacturing parts of a fuel cell stack, and more particularly, the present invention relates to an apparatus for manufacturing a Membrane-Electrode Assembly (MEA), which is used to manufacture an MEA for a fuel cell.
(b) Description of the Related Art
A fuel cell produces electricity by electrochemical reactions between hydrogen and oxygen and generates electricity using external chemical reaction materials without a separate charging process. The fuel cell may include separating plates or bipolar plates with a membrane-electrode assembly (MEA) disposed therebetween. A plurality of fuel cells may be continuously arranged to form a fuel cell stack.
FIG. 1 is a cross-sectional view schematically illustrating an example of a known membrane-electrode assembly according to the related art. Referring to FIG. 1, an exemplary membrane-electrode assembly 1, that is, a core element of the fuel cell, includes an anode and a cathode, that is, electrode catalyst layers 5, on both sides of an electrolyte membrane 3 through which hydrogen ions move. Additionally, the membrane-electrode assembly 1 includes sub-gaskets 7 that protect the electrode catalyst layers 5 and the electrolyte membrane 3 and secure the assembly of the fuel cells.
In a method of manufacturing the membrane-electrode assembly 1, first, an electrode membrane sheet 6 is manufactured using a decal method of unwinding the electrolyte membrane 3 wound in a roll form and consecutively transferring the electrode catalyst layers 5 onto both faces of the electrolyte membrane 3 at a specific interval (e.g., at a pitch of about 150 mm) Thereafter, a membrane-electrode assembly sheet is manufactured using a roll-to-roll method of unwinding and transferring the electrode membrane sheet 6 wound in a roll form, unwinding the sub-gaskets 7 of a roll form and placing the unwound sub-gaskets on both faces of the electrode membrane sheet 6, passing them through hot rollers, and bonding the sub-gaskets 7 on both faces of the electrode membrane sheet.
Particularly, the sub-gaskets 7 are in a state in which electrode windows and manifold windows for opening the electrode catalyst layers 5 are cut. The sub-gaskets 7 may enter both faces of the electrode membrane sheet and may be bonded to both faces of the electrode membrane sheet. After the processes described above is complete, the membrane-electrode assembly sheet wound in a roll form is unwound and cut into a unit form including the electrode catalyst layers 5, to thus manufacture the membrane-electrode assembly 1 as shown in FIG. 1.
In the membrane-electrode assembly 1 of the related art manufactured as described above, the electrode membrane sheet 6 includes the electrode catalyst layers 5 consecutively formed on both faces of the electrolyte membrane 3, and the sub-gaskets 7 are bonded to both faces of the electrode membrane sheet. Accordingly, the electrolyte membrane 3 is disposed in the entire region between the sub-gaskets 7. The development direction of the sub-gaskets 7 used in the membrane-electrode assembly 1 is related to the leakage prevention of a reaction gas or to cell output performance. An effect of the sub-gaskets 7 has not been approved with respect to the mechanical durability of the membrane-electrode assembly 1 and the electrolyte membrane 3.
Accordingly, in the related art, the electrolyte membrane 3 is present in portions where electricity is not generated, that is, the exterior regions of the electrode catalyst layers 5 that generate electricity, since the sub-gaskets 7 related only to the prevention of a leakage of reaction gas and cell output performance are bonded together with the electrolyte membrane 3 interposed therebetween in the portion. Therefore, relatively expensive electrolyte membrane materials are wasted since the electrolyte membrane 3 supporting the sub-gaskets 7 is present in the portion of the membrane-electrode assembly 1 in which electricity is not generated. Thus, the manufacturing costs of the membrane-electrode assembly 1 may increase accordingly.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.